I’ve written it before—New York City is the greenest place on Earth. Not actual green—despite the manicured beauty of Central and Prospect Parks, as of 2007 New York had fewer greens spaces per acre than just about any other major American city. But thanks chiefly to population density, New Yorkers have just about the smallest carbon footprint in the U.S. When it comes to just about every natural resource—including space, which ultimately might be the most scarce of all—New Yorkers do it more efficiently. Which is what you get for $3,832 a month, the average rent last month in Manhattan. (I live in Brooklyn.)

But there’s one green thing New Yorkers do not do well: recycle. The city manages to divert only about 15% of its waste from landfills to recycling centers, which compares to about 34% nationwide. It’s not really clear why. New York Mayor Michael Bloomberg actually suspended curbside recycling for two years early in his first term, hoping to save money. The fact that a lot of New Yorkers live in small apartments where even a single additional recycling bin can take up valuable space might erode recycling rates. (A bin might be one sq. ft, which rents for an average of $51.13 in New York.) And curbside pickup itself might play a role—with neighbors trash easily intermingling, it’s hard to tell who’s recycling and who’s not, and even harder to fine them.

With less than a half a year left to go on his third and final (we assume) term, however, Bloomberg seems determined to fix the recycling problem. He’s already cracking down on recycling scofflaws, with more to come as the Sanitation Department beefs up enforcement. Earlier this year he announced that rigid plastics, including toys and ubiquitous food containers, would be able to be recycled. He’s said that he wants the city to reuse 70% of its waste by 2030. Last year he appointed Ron Gonen, the co-founder of the innovative startup RecycleBank, as the city’s first recycling czar.

And now Bloomberg says he’s going to tackle what he called earlier this year “New York’s final recycling frontier”: food waste. But can he make New Yorkers learn to compost?

According to the New York Times, which first reported the plan on June 16, New York will soon announce that it will soon hire a composting plant capable of handling 100,000 tons of food scraps per year—about 10% of the city’s residential food waste. And city hall will soon seek proposals to build another plant that will process food waste into biogas, to be burned for electricity. But the real news is that soon enough, New Yorkers will likely be required—under pain of fine—separate out food scraps for curbside pickup, just as they do now (or are supposed to do) for plastics, glass and paper.

150,000 single-family homes—which do indeed exist in New York City—will begin a pilot program next year, along with 100 apartment buildings. New York has already tried a similar pilot program out on Staten Island—home to single-family houses in the city—and has seen success rates of nearly 50%. Food waste and organics account for about a third of residential trash in New York, and the city claims that it could save about $100 million a year by recycling it, chiefly by using it as fertilizer or for biogas.

New York won’t be the first city to try municipal food recycling. Toronto, Portland, Seattle and countless other cities have experimented with wide-scale composting, with San Francisco—the first city to do so—collecting more than 1 million tons of organic waste since the program was begun more than 16 years ago. Combined with recycling, that’s allowed the city to divert more than 80% of total waste generated each year from landfills.

I don’t think New York is going to approach San Francisco’s success—the Bay Area city actually brews organic fertilizers from its food waste and sells then to local vineyards. New York’s vaunted greenness is mostly a passive result of the city’s layout. It’s not that we consciously try to use less energy—just check out the way we abuse window air conditioner units on a hot summer day. It’s that density obviates the need for travel, and small living spaces obviate the need for lots of energy to heat or cool our residences. But recycling requires conscious effort—sorting out the glass from the plastics, and now the leftover Chinese food from the paper bag it came in. The numbers say that so far, many New Yorkers haven’t been willing to make that effort. Let’s see if Bloomberg can change that.